Y染色体STR基因座DYS385等位基因分型标准物的制备及群体遗传学研究

目的　采用分子克隆技术大量制备优质标准 STR基因座等位基因分型标准物 ,解决长期困扰STR分型上存在的准确性和标准化问题。方法　先用 PCR扩增出 Y染色体上 DYS385基因座的 9个等位基因片段 ,将其插入 p U C重组质粒中 ,经 DNA测序分析证实插入片段的结构及大小 ,按国际标准将插入的等位基因片段进行命名 ,最后经转染、扩大培养、扩增及再鉴定后制备出标准的 DYS385等位基因分型标准物。结果　应用此法制备出大量的 DYS385等位基因分型标准物 ,并将其成功地应用于该基因座在中国成都地区汉族及德国美茵茨地区高加索人群体中的基因型分布频率调查。结论　该法制备的 STR基因座等位基因分型标准物在法科学实践中应用价值极高 ,DYS385基因座是一个适合我国群体分析和法科学应用的遗传标记

Study on the Construction of DYS385 Allelic Ladder and the Genotype Distribution in Two Populations

Objective We have designed a new method to produce standardDYS385 allelic ladder in order to solve the problem of the accuracy and standardization of STR-PCR typing in forensic practice. Methods Nine different PCR amplified DYS385 allelic fragments were isolated from the gel, eluted into the distilled water and reamplified by PCR. The purified allelic fragments were then blunt-end subcloned individually into the pUC plasmid vectors and transfected into competent E.coli DH5αTM cells. The sequencing results confirmed that the size and the constructure of the inserts were correct. The recombinant plasmids DNA with 9 inserts were then used as templates for reamplification to generate DYS385 standard ladder. Results A large quantity of standard DYS385 allelic ladder was obtained, with which the genetic polymorphisms of DYS385 locus both in Chinese Han and German populations were studied. Conclusion The STR standard ladder constructed by this method has high value in the forensic application, and the DYS385 locus is robust for forensic analysis.